Large-scale integrated quantum photonic technologies will require on-chip integration of identical photon sources with reconfigurable waveguide circuits. Relatively complex quantum circuits have been ...demonstrated already, but few studies acknowledge the pressing need to integrate photon sources and waveguide circuits together on-chip. A key step towards such large-scale quantum technologies is the integration of just two individual photon sources within a waveguide circuit, and the demonstration of high-visibility quantum interference between them. Here, we report a silicon-on-insulator device that combines two four-wave mixing sources in an interferometer with a reconfigurable phase shifter. We configured the device to create and manipulate two-colour (non-degenerate) or same-colour (degenerate) path-entangled or path-unentangled photon pairs. We observed up to 100.0 ± 0.4% visibility quantum interference on-chip, and up to 95 ± 4% off-chip. Our device removes the need for external photon sources, provides a path to increasing the complexity of quantum photonic circuits and is a first step towards fully integrated quantum technologies.
In the central nervous system (CNS), the expression of molecules is strictly regulated during development. Control of the spatiotemporal expression of molecules is a mechanism not only to construct ...the functional neuronal network but also to adjust the network in response to new information from outside of the individual, i.e., through learning and memory. Among the functional molecules in the CNS, one of the best-studied groups is the neurotrophins, which are nerve growth factor (NGF)-related gene family molecules. Neurotrophins include NGF, brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and NT-4/5 in the mammal. Among neurotrophins and their receptors, BDNF and tropomyosin- related kinases B (TrkB) are enriched in the CNS. In the CNS, the BDNF-TrkB signaling pathway fulfills a wide variety of functions throughout life, such as cell survival, migration, outgrowth of axons and dendrites, synaptogenesis, synaptic transmission, and remodeling of synapses. Although the same ligand and receptor, BDNF and TrkB, act in these various developmental events, we do not yet understand what kind of mechanism provokes the functional multiplicity of the BDNF-TrkB signaling pathway. In this review, we discuss the mechanism that elicits the variety of functions performed by the BDNF-TrkB signaling pathway in the CNS as a tool of pharmacological therapy.
(a) Artificial delamination in the CFRP specimen, (b) group velocity distribution, and (c) 3D imaging in the CFRP specimen. Display omitted
A pulsed laser illuminates a target zone that causes rapid ...thermoelastic expansion, generating broadband high-frequency ultrasonic wave (photoacoustic wave, PA wave). We developed a PA microscopy (PAM) with a confocal area of laser and ultrasonic wave for applications in nondestructive testing (NDT). The synthetic aperture focusing technique (SAFT) is applied in the PAM for the three-dimensional (3D) imaging of interior flaws. Here, we report proof-of-concept experiments for the NDT of a subsurface flaw in a thin laminar material. Graphical abstract (a) shows a specimen of carbon-fiber-reinforced plastic (CFRP) with an artificial delamination. Here, it should be noted that the group velocity varies directionally due to the strong anisotropy of the CFRP specimen (see Graphical abstract (b)). By considering the group velocity distribution in the SAFT, the shape and location of the subsurface delamination were accurately estimated as shown in Graphical abstract (c). Coating the surface of the CFRP specimen with a light-absorbent material improved the amplitude of the PA wave. This finding showed that the signal-to-noise ratio of the waves scattered from the flaws can be improved.
Integrated quantum photonic waveguide circuits are a promising approach to realizing future photonic quantum technologies. Here, we present an integrated photonic quantum technology platform ...utilizing the silicon-on-insulator material system, where quantum interference and the manipulation of quantum states of light are demonstrated in components orders of magnitude smaller than previous implementations. Two-photon quantum interference is presented in a multi-mode interference coupler, and the manipulation of entanglement is demonstrated in a Mach-Zehnder interferometer, opening the way to an all-silicon photonic quantum technology platform.
In this study, we used a flexible array transducer to obtain images of flaws in materials with irregular surfaces. The transducer was manufactured from a 1–3 composite made of piezoelectric zirconate ...titanate and epoxy resin, and covered with neoprene rubber layers. An approach that involved combining a flexible array transducer and full matrix capture (FMC) is effective, because the surface geometry and flaw signal data can be separately measured and merged during post-processing. The disadvantage of the flexible array transducer is its narrow frequency band due to the thin damping material. To enhance the spatial resolution, we used the scattering amplitude extracted from raw signal data. We also introduced a numerical apodization technique to suppress the influence of side lobe. We validated the performance of the proposed method by measuring the signals from artificial flaws in aluminum specimens, performing high-speed FMC imaging using graphic processing unit computation.
Background
Chronically ill children are increasingly expected to join their peers in regular classrooms. However, sometimes schools do not provide adequate assistance. This study explores nursing ...teachers' thoughts and experiences on integrating such students into regular classrooms in Japan.
Methods
We analysed 79 essays written by nursing teachers collectively titled ‘The challenges of having chronically ill children in regular classrooms’. We conducted a qualitative study using Kinoshita's Modified Grounded Theory Approach.
Results
Nursing teachers identified three main obstacles: insufficient resources to support chronically ill students, parents not playing a supporting role in aiding them at school and a regular classroom not being suitable for them. However, collaborating with the children's medical staff proved successful at integrating them into regular classrooms.
Conclusions
Given these obstacles, it seems very difficult for nursing teachers to lead the way toward establishing cooperative support systems for the children. Instructions from medical staff could empower teachers to set up such systems.
In the field of basic and clinical neurosciences, it is important to develop a method for easy delivery and persistent expression of transgene in central neurons. We firstly generated lentiviral ...vectors with five kinds of neuron-specific promoters, such as synapsin I (SYN), calcium/calmodulin-dependent protein kinase II, tubulin alpha I, neuron-specific enolase and platelet-derived growth factor beta chain promoters and then novel hybrid promoters by fusing cytomegalovirus enhancer (E) to those neuron-specific promoters. Neuron-specific expression of green fluorescent protein (GFP) with those promoters was examined in vivo by injecting the lentiviral vectors into the rat neostriatum, thalamus and neocortex. Among all the promoters, SYN promoter displayed the highest specificity for neuronal expression in all the regions examined (more than 96%). Although GFP production by the hybrid promoters was about 2-4 times larger than the non-enhanced promoters, the neuronal specificity was significantly decreased in most cases. However, the neuronal specificity of E/SYN hybrid promoter exhibited the least decrease only in the thalamus. Furthermore, the transcriptional activity and neuronal specificity of E/SYN promoter were sustained for up to 8 weeks. Thus, lentivirus with E/SYN promoter is the best vector for strong persistent expression in neurons.
Introduction
Most children with haemophilia in Japan study in mainstream schools. However, many mothers have difficulty deciding whether to inform teachers of their child's haemophilia because of the ...accompanying potential discrimination and prejudice, particularly after the press coverage on the HIV scandal in the 1980s.
Aims
We therefore aim to explore and describe disclosure strategies of mothers of children with haemophilia.
Methods
A qualitative study was conducted using the modified grounded theory approach to explore disclosure strategies of mothers of children with haemophilia. Semi‐structured interviews were conducted with 19 selected mothers (12 children were HIV positive and 7 were HIV‐negative).
Results
In the pre‐HIV/AIDS crisis period, the kind of strategy employed – full disclosure, conditional full disclosure and partial disclosure – depended on the extent of mothers’ fears about mainstream schools refusing admission because of their child's haemophilia. After the HIV/AIDS crisis in the 1980s in Japan, the three categories of strategies employed by mothers of children with haemophilia were limited disclosure, non‐disclosure and full disclosure. These depended on mothers’ expectations of discrimination towards their child because of the social stigma around haemophilia and being HIV‐positive.
Conclusion
For children with haemophilia to feel safe attending school, public schools must establish care management and anti‐discrimination systems for children with chronic diseases, thus assuring parents of their children's welfare at school.
Microstructure, high-temperature compressive and tensile deformation, and oxidation property of multi-phase intermetallic alloys, which were based on the Ni3Si-Ni3Ti-Ni3Nb pseudo-ternary alloy system ...and composed of L12, D024 and D0a phases, were investigated. The microstructures of these multi-phase intermetallic alloys were largely dependent on alloy composition. The Widmanstatten-like Ni3Ti(D024) phase was precipitated from L12 matrix by a solid-state reaction, accompanied with a certain orientation relationship and habit plane. The tensile stress as well as the tensile elongation of these multi-phase alloys increased with increasing Si content, i.e. the volume fraction of L12 phase in the wide range of test temperatures. Fifty parts per million boron addition to these multi-phase intermetallic alloys resulted in increased tensile stress and tensile elongation. It was found that the multi-phase intermetallic alloy with a high Si content had good oxidation resistance, accompanied with a continuous silicate layer. From an overall evaluation of the properties examined, it was shown that the multiphase intermetallic alloy that had a high Si content and was composed of L12 matrix dispersed by D024 and D0a phases had the most favorable properties as high-temperature mechanical and chemical materials.
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